Roger Federer Stunned by Federico Delbonis in Hamburg

Roger Federer's Hamburg campaign came to a screeching halt in Saturday's semifinals, with the top seed and world No. 5 falling 7-6(7) 7-6(4) to unheralded Argentinian qualifier Federico Delbonis.

The buzz surrounding Federer's performances this week was centered around his new Wilson frame—the Swiss superstar switched from a 90-inch square frame to a 98-inch square frame, his first racket alteration in a decade.

While successful in his first three matches with the new stick, the Swiss was undone by sloppy baseline play and poor returning in the semifinal. The 114th-ranked Delbonis, a tall, powerful, lanky lefty, channeled Federer's nemesis Rafael Nadal by using a cunning mix of bold aggression and dogged retrieving to score the upset.

Federer was particularly plagued by inconsistency at crucial moments at the end of both sets. He failed to convert three set points in the first set—including one in the tiebreaker—and made a flurry of backhand errors in the second set tiebreak to gift Delbonis match points.

"My key was to enjoy the match and enjoy playing this kind of player, because he's the best of all-time," commented Delbonis after the match.

According to the ATP World Tour website, Delbonis becomes the third qualifier to reach an ATP final this season. He goes on to face Fabio Fognini in the championship match on Sunday. The Italian, hot off his first title last week in Stuttgart, dispatched Spaniard Nicolas Almagro in straight sets in the other semifinal, 6-4, 7-6(3).